Concrete platform

ABSTRACT

A concrete platform has at a top portion, a table-deck portion that has a form, a load portion formed in the form, and an attachment part. The form has a cross-sectional U-shape, and is formed by a pair of concrete side walls and a concrete bottom plate that connects the pair of concrete side walls. The form has reinforcing members provided to extend linearly in a longitudinal direction inside the concrete side walls and inside the concrete bottom plate.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. Ser. No. 13/148,812filed on August 10, which is a National Phase of InternationalApplication No. PCT/JP2010/050018 filed on Jan. 5, 2010. The applicationclaims priority to Japanese patent application number 2009-149634 filedon Jun. 24, 2009, which is incorporated by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a concrete platform onto which a heavystructure, such as a turbine, a generator, and so forth, is mounted.

BACKGROUND ART

In general, a known concrete platform on which is mounted a heavystructure that vibrates during operation, such as a turbine, agenerator, and so forth, is constructed with a large volume of massconcrete and reinforcing bars.

A beam etc. of a table-deck portion in such a concrete platform, ontowhich a heavy structure is mounted, is formed to have a largercross-sectional area (for instance, having a width equal to or more than2 m and a height equal to or more than 2 m) in comparison with a beamthat is used for buildings such as condominiums etc., so as to be ableto support a heavy load. At the same time, many metal parts used forfixing the above-mentioned heavy structure to the table-deck portion areembedded in the table-deck portion. The embedded metal parts can includetemplates, bolts, anchor blocks, and so forth.

Upon producing (hereinafter referred to as “building”) the concreteplatform as mentioned above, form is put in place, and fresh concrete issubsequently introduced inside the form, in other words, fresh concreteis poured.

Known form includes one that is removed after the concrete is poured(for example, see PTL 1) and one that makes up part of a concreteplatform without being removed (for example, see PTL 2).

For example, when the concrete platform is built using the formdescribed in PTL 1, in order to construct a reinforced concrete beam,which has a large sectional area, of the table-deck portion, the form,supports for supporting the form, scaffolding, and so forth are firstput in place. Thereafter, fresh concrete is poured. Once the reinforcedconcrete beam has been constructed, the form, the support, thescaffolding, and so forth are removed.

For example, when the concrete platform is built using the formdescribed in PTL 2, in other words, steel form, in order to construct areinforced concrete beam, which has a large sectional area, of thetable-deck portion, as in the case with PTL 1, fresh concrete is pouredafter the steel form, supports for supporting the form, scaffolding, andso forth are put in place first.

Although the supports, the scaffolding, and so forth are removedthereafter, the steel form is not removed and it makes up part of theconcrete platform.

CITATION LIST Patent Literature

{PTL 1} Japanese Unexamined Patent Application, Publication No.2001-027281

{PTL 2} Japanese Unexamined Patent Application, Publication No. Shou59-006495

SUMMARY OF INVENTION Technical Problem

However, because the form, the supports, the scaffolding, and so forthare required in the process described in the above-mentioned PTL 1,there has been a problem in that the construction period required forbuilding a concrete platform is extended. In particular, there have beenproblems in that the form and the supports for supporting the form mustbe put in place and then removed, which extends the construction period.

At the same time, because embedded metal parts that are embedded in thetable-deck portion are required to be set at a prescribed accuracy,there has been a problem in that the construction period is extendedeven further.

On the other hand, because the steel form, which is fabricated in afactory, is used in the process described in the above-mentioned PTL 2,a reduction in the construction period at the building site of theconcrete platform can be achieved.

However, when the steel form is used, because the steel form deformsupon pouring of the fresh concrete, additional separate supports arerequired for supporting the steel form. Therefore, the separate supportsare required to be put in place and then removed, resulting in theproblem that the construction period is extended.

Because the steel form is made of steel, the steel form is required tobe produced in a factory, and this results in the need for transport ina container. Thus, there has been a problem in that, in comparison withconventional form made of wood, the cost of the transport etc. becomeshigh.

The present invention has been conceived to solve the problems describedabove, and an object thereof is to provide a concrete platform capableof reducing a construction period in a concrete platform productionprocess and capable of preventing an increase in the costs of buildingthe concrete platform.

Solution to Problem

In order to realize the object described above, the present inventionprovides the following solutions.

A process for producing a concrete platform according to a first aspectof the present invention is a process for producing a concrete platformon which an object to be supported is fixed, including: a step offorming form having a pair of concrete side walls and a concrete bottomslab that connects the pair of side walls; a step of setting the form ona plurality of piers; and a step of pouring concrete into the form thatis set on the plurality of piers.

According to a process for producing a concrete platform according tothe first aspect of the present invention, the step of making the formand the step of building the plurality of piers can be conductedsimultaneously, and at the same time, the form can be made at adifferent site from the construction site of a plurality of piers, inother words, the construction site of the concrete platform. Therefore,a reduction in the construction period, that is, the production periodof the concrete platform, can be afforded.

Furthermore, because the form is made of concrete, the form is notrequired to be removed after the concrete has been poured into the form,and therefore, the construction period can be reduced.

On the other hand, when form made of steel plates is used, it isnecessary to perform welding management, and it is necessary to make theform in a factory in order to ensure dimensional precision. In contrast,when form made of concrete is used, because the form can be madeintegrally, it is not necessary to perform welding management etc.Therefore, the site for producing the form is not limited to thefactory; the form can be produced at a suitable site close to theconstruction site, and it is possible to reduce the costs related totransport of the form.

Furthermore, because concrete is poured after the form having the pairof side walls and the bottom slab has been set on the piers, a reductionin the size of a crane used for setting the form can be affordedcompared with a case where the form into which concrete has been pouredis set on the piers, or a case where a concrete table-deck portion fromwhich the form has been removed after concrete has been poured is set onthe piers.

In the process for producing a concrete platform according to the firstaspect of the present invention, in the step of setting the form on theplurality of piers, the form may be set on the plurality of piers aftera connecting member that connects each of the upper edge portions of thepair of side walls of the form by being placed on the upper edgeportions is attached to the pair of side walls.

According to this configuration, by connecting each of the upper edgeportions of the pair of side walls by the connecting member, a part ofthe cross-section of the form forms a box-structure; therefore, it ispossible to prevent a reduction in the sectional stiffness of form dueto the widening of the gap between the side wall edge portions (upperedges). Therefore, deformation of the form during pouring of theconcrete is prevented, and no supports for supporting the form need tobe set.

On the other hand, if steel form is used, in order to prevent areduction in the sectional stiffness of the form, stiffening parts formaintaining the relative positions between the side walls and the bottomslab may be provided on the bonding portions between the side walls andthe bottom slabs. However, if the stiffening parts are provided, becausethe internal cross-sectional area (internal space) of the form becomessmaller, the space available for arranging the reinforcing bars(internal space in the form) will be limited.

In this case, in the space for arranging the reinforcing bars of theform, the reinforcing bars will not be able to be arranged in the regionin the vicinity of the bottom slab, where the bending stress actingthereon is large. As a result, the strength of the table-deck portioncan be lowered. In the case of concrete form, which has a greater formthickness compared with steel form, the impact is particularlysignificant. This problem can be solved by connecting each of the upperedge portions of the pair of side walls by using the connecting memberin the present invention.

In the process for producing a concrete platform according to the firstaspect of the present invention, an attachment part that is partiallyembedded in concrete that is poured into the form so as to fix theobject to be supported may be aligned with the connecting member in apositionable manner.

According to this configuration, because the arrangement positions ofthe attachment parts are maintained with the connecting member, it ispossible to align the attachment parts easily and with high precisionwithout using a separate massive template and temporary supportingmembers that temporarily support this template from above. Furthermore,the construction period can be reduced compared with a process where theattachment parts are arranged directly in the form and their arrangementpositions are adjusted.

Here, the attachment part can include, for example, a metal part that isused for fixing a heavy structure that is mounted on the concreteplatform, and can include an embedded metal part etc., such as an anchorbolt.

In the process for producing a concrete platform according to the firstaspect of the present invention, the connecting member may be removedfrom the upper edge portions of the pair of side walls after the step ofpouring concrete.

According to this configuration, it is possible to reuse the connectingmember.

A concrete platform according to a second aspect of the presentinvention is produced by the process for producing a concrete platformaccording to the above-mentioned present invention.

According to the concrete platform of the second aspect of the presentinvention, by making the form from concrete, the form is not required tobe removed, and it is possible to reduce the construction periodcompared with a case where form made of wood etc. is used.

In addition, when steel form is used, it is necessary to perform weldingmanagement, and it is necessary to make the form in a factory in orderto ensure dimensional precision. In contrast, when form made of concreteis used, it is not necessary to perform welding management etc.Therefore, the site for producing the form is not limited to a factory;the form can be produced at a suitable site close to the constructionsite, and it is possible to reduce costs related to transport of theform.

A connecting member according to a third aspect of the present inventionis a connecting member that is used in the process for producing aconcrete platform according to the above-mentioned present invention,including: an elongated member that is formed to have substantially thesame length as the gap between the pair of side walls of the form; afixing member that anchors the attachment part to the elongated member;and an adjusting part that enables the attachment part to move along thetop surface of the table-deck portion that is formed by pouring concreteinto the form.

According to the connecting member of the third aspect of the presentinvention, the connecting member is composed of an elongated member,thereby affording weight saving. By doing so, the connecting member caneasily be attached to and detached from the form. In addition, by usingthe adjusting parts, the arrangement positions of the attachment partsare two-dimensionally adjustable along the top surface of the table-deckportion, in other words, in the horizontal plane.

Advantageous Effects of Invention

According to a concrete platform production process, a concreteplatform, and a connecting member of the present invention, form havinga pair of concrete side walls and a concrete bottom slab that connectsthe pair of side walls is formed, and concrete is poured into the formafter the form is set on a plurality of piers; therefore, advantages areafforded in that the construction period can be reduced, and an increasein the building costs can be prevented.

BRIEF DESCRIPTION OF DRAWINGS

{FIG. 1} FIG. 1 is a schematic view for explaining the configuration ofa turbine generator platform according to one embodiment of the presentinvention.

{FIG. 2} FIG. 2 is a sectional view, taken along line A-A, forexplaining the configuration of the table-deck portion of FIG. 1.

{FIG. 3} FIG. 3 is a view for explaining construction steps of theplatform in FIG. 1.

{FIG. 4} FIG. 4 is a schematic view for explaining a state in whichpiers in FIG. 1 are constructed.

{FIG. 5} FIG. 5 is a sectional view for explaining the configuration ofform in FIG. 1.

{FIG. 6} FIG. 6 is a schematic view for explaining a state in which theform is set on the piers in FIG. 4.

{FIG. 7} FIG. 7 is a perspective view for explaining the configurationof the form that is set on the piers in FIG. 6.

{FIG. 8} FIG. 8 is a sectional view for explaining the configuration ofthe form in FIG. 6 before inner concrete is poured.

{FIG. 9} FIG. 9 is a schematic view for explaining a state forconstructing connecting portions between the piers and the form.

DESCRIPTION OF EMBODIMENTS

A platform according to an embodiment of this invention will bedescribed with reference to FIGS. 1 to 9.

FIG. 1 is a schematic view for explaining the configuration of a turbinegenerator platform according to this embodiment.

A platform (concrete platform) 1 is a structure onto which a turbine (asteam turbine or a gas turbine) or a generator is mounted and is astructure mainly formed of concrete and reinforcing bars.

In this embodiment, the present invention is described as applied to theplatform 1 onto which a turbine or a generator is mounted. However, theobject to be mounted on the platform 1 is not limited to a turbine or agenerator, and it includes other heavy structures, including those thatvibrate during operation; it is not particularly limited.

As shown in FIG. 1, the platform 1 is mainly provided with a pluralityof piers 2 and a table-deck portion 3.

As shown in FIG. 1, the piers 2 are members that extend upwards from theground G, and are mainly formed of concrete and reinforcing bars tosupport the table-deck portion 3. Known structures can be used for thepiers 2, and they are not particularly limited.

As shown in FIG. 1, the table-deck portion 3 is a beam member that isarranged over the upper ends (the ends at the upper side in FIG. 1) ofthe piers 2, and a turbine or a generator is mounted thereon.

FIG. 2 is a sectional view, taken along line A-A, for explaining theconfiguration of the table-deck portion in FIG. 1.

As shown in FIGS. 1 and 2, the table-deck portion 3 is mainly providedwith form 4, a load portion 5, embedded metal parts (attachment parts)6, and so forth.

As shown in FIG. 2, the form 4 forms the side surfaces and the bottomsurface of the table-deck portion 3, and the load portion 5, theembedded metal parts 6, and so forth are arranged inside the form 4.Furthermore, the form 4 is formed so as to have a U-shapedcross-section, and so as to extend between the piers 2.

The form 4 is mainly formed of concrete and reinforcing bars, and asshown in FIG. 2, is produced in one integral form from a bottom slab 42and a pair of side walls 41 that are erected on both edges of thisbottom slab 42. The form 4 can have a size, for example, equal to ormore than 2 m in width and equal to or more than 2 m in height.

The respective side walls 41 are formed into a plate shape, and theyform the side surfaces of the table-deck portion 3 and also the sidesurfaces of the form 4. The side walls 41 can have a size of, forexample, about 150 mm to 200 mm in plate thickness and equal to or morethan 2 m in the height-wise dimension.

The side walls 41 are mainly provided with side-wall concrete portions41A and side-wall tension parts 41B.

The side-wall concrete portions 41A mainly form the side walls 41, andthey are precast concrete that has been poured separately from an innerconcrete portion 51 in the load portion 5.

The side-wall tension parts 41B are linear reinforcing members extendingin the longitudinal direction of the table-deck portion 3 (a directionperpendicular to the plane of the drawing in FIG. 2), and the side-walltension parts 41B compress the side-wall concrete portions 41A in theirlongitudinal direction, by being arranged inside the side-wall concreteportions 41A in a state tensioned in the above-mentioned longitudinaldirection.

This embodiment is described as applied to an example in which theside-wall tension parts 41B are arranged on the upper edge side of theside-wall concrete portions 41A (the upper edge portion side in FIG. 2).

The bottom slab 42 is formed into a plate-shape, and the bottom slab 42forms the bottom surface of the table-deck portion 3 and also the bottomsurface of the form 4. The bottom slab 42 can have a size of, forexample, about 150 mm to 200 mm in plate thickness and equal to or morethan 2 m in the width-wise dimension.

The bottom slab 42 is mainly provided with a bottom slab concreteportion 42A and bottom slab tension parts 42B.

The bottom slab concrete portion 42A mainly forms the bottom slab 42,and it is precast concrete that has been poured separately from theinner concrete portion 51 in the load portion 5.

The bottom slab tension parts 42B are linear reinforcing membersextending in the longitudinal direction of the table-deck portion 3, andthe bottom slab tension parts 42B compress the bottom slab concreteportion 42A in its longitudinal direction, by being arranged inside thebottom slab concrete portion 42A in a state tensioned in theabove-mentioned longitudinal direction.

This embodiment is described as applied to an example in which aplurality of bottom slab tension parts 42B are arranged in one line, atequal intervals, within the bottom slab concrete portion 42A.

Known members, such as wires, reinforcing bars, and so forth, can beused as the side-wall tension parts 41B and the bottom slab tensionparts 42B, and they are not particularly limited.

This embodiment illustrates an example in which the side walls 41 andthe bottom slab 42 forming the form 4 are produced in one integral form;however, the embodiment is not particularly limited to this form, andseparately produced ones may be connected.

The load portion 5 is arranged inside the form 4 to form the table-deckportion 3 together with the form 4 and supports a turbine or a generatorthat is mounted on the table-deck portion 3.

The load portion 5 is mainly provided with the inner concrete portion 51and inner reinforcing bars 52.

The inner concrete portion 51 mainly forms the load portion 5 and mainlyreceives force related to compressive stress among the forces acting onthe table-deck portion 3. Furthermore, the inner concrete portion 51 isformed by pouring concrete into the form 4 and is formed separately fromthe side-wall concrete portions 41A and the bottom slab concrete portion42A of the form 4.

The inner reinforcing bars 52 are linear reinforcing members that havebeen placed throughout the load portion 5 and that mainly receive theforce related to tensile stress among the force acting on the table-deckportion 3. Any known arrangement pattern can be used for the innerreinforcing bars 52, and it is not particularly limited.

As shown in FIGS. 1 and 2, the embedded metal parts 6 are partiallyembedded in the top surface (the surface on the upper side in FIG. 1) ofthe table-deck portion 3 and are used for fixing a turbine or agenerator that is to be mounted on the table-deck portion 3. Examples ofthe embedded metal parts 6 can include anchor bolts, anchor blocks andso forth.

A construction step (production process) of the platform 1 having theabove-mentioned configuration will be explained below.

FIG. 3 is a view for explaining a construction step of the platform inFIG. 1. FIG. 4 is a schematic view for explaining a state in which thepiers in FIG. 1 are constructed. FIG. 5 is a sectional view forexplaining the configuration of the form in FIG. 1.

As shown in FIGS. 3 and 4, in the construction of the platform 1 of thisembodiment, a step for constructing the piers 2 (Step S1) is conducted,and as shown in FIGS. 3 and 5, a step for forming the form 4 (Step S2)is conducted concurrently.

As shown in FIG. 4, in the step for constructing the piers 2, aplurality of piers 2 are constructed on the ground G.

On the other hand, as shown in FIG. 5, in the step for forming the form4, the form 4, having the pair of side walls 41 and the bottom slab 42that are arranged in the U-shape, is formed at a different site from theconstruction site of the platform 1. More specifically, when theside-wall concrete portions 41A of the side walls 41 and the bottom slabconcrete portion 42A of the bottom slab 42 are formed, the side-walltension parts 41B and the bottom slab tension parts 42B are respectivelyembedded in a longitudinal tensioned state. By doing so, compressivestress in the longitudinal direction is applied to the side-wallconcrete portions 41A and the bottom slab concrete portion 42A.

By doing so, for example, even when the table-deck portion is deformeddownward and tensile force acts on the form 4 that forms the sidesurfaces and the bottom surface of the table-deck portion, because thecompressive stress is pre-applied to the side-wall concrete portions 41Aand the bottom slab concrete portion 42A, the tensile stress isprevented from acting, or the tensile stress is reduced.

The thus-formed form 4 is transported to the construction site of thepiers 2, in other words, the construction site of the platform 1, bytransportation means, such as a trailer.

FIG. 6 is a schematic view for explaining a state in which the form isplaced on the piers of FIG. 4.

Once the form 4 is transported to the construction site of the platform1, a step of setting the form 4 on the piers 2, as shown in FIGS. 3 and6, is conducted (Step S3).

FIG. 7 is a perspective view for explaining the configuration of theform that is set on the piers in FIG. 6.

As shown in FIG. 7, when the form 4 is set on the piers 2, anupper-surface connecting part (connecting member) 7 is set on the form4. The upper-surface connecting part 7 is arranged over the upper edgeportions of the side walls 41 of the form 4 so as to connect the upperedge portions of the pair of side walls 41.

The upper-surface connecting part 7 is an elongated member that isformed to have substantially the same length as the gap between the pairof side walls 41 of the form 4. The upper-surface connecting part 7 isprovided with two slotted holes 71 that extend in the longitudinaldirection of the upper-surface connecting part 7 so as to be alignedalong the longitudinal direction.

In addition, the upper-surface connecting part 7 is provided with, onthe four corners thereof, projecting portions 74, each having a slottedhole 75 that extends in the width-wise direction of the upper-surfaceconnecting part 7. The embedded metal parts 6 are anchored to theupper-surface connecting part 7 by being fastened by nuts 61 in a stateinserted though the slotted holes 71.

By attaching the upper-surface connecting part 7, the part of the form 4having a U-shaped cross-section forms a box-structure; therefore, it ispossible to prevent a reduction in the sectional stiffness due towidening of the gap between the side-wall edge portions (the upperedges). Therefore, when the form 4 is hoisted, when the form 4 is set ona plurality of piers 2, and then, when concrete is poured into the form4 to form the inner concrete portion 51, because the gap between theupper edges of the side walls 41 does not become wider, the form 4becomes more resistant to deformation.

The upper-surface connecting part 7 is attached to the form 4, forexample, as described below.

The upper-surface connecting part 7 is first positioned such that theupper-surface connecting part 7 is set over the upper edge portions ofthe pair of side walls 41. Next, as shown in FIG. 7, anchor bolts 73 areinserted into the respective slotted holes 75 provided in the projectingportions 74. Then, these anchor bolts 73 are fastened to the upper edgeportions of the pair of side walls 41.

Side panels 72 are bonded to both side surfaces (both end surfaces inlongitudinal direction) of the upper-surface connecting part 7 bywelding or another bonding process. Here, only the upper half portionsof the side panels 72 are bonded. Therefore, the lower portions of theside panels 72 can hold the pair of side walls 41 from both sides. Inthis way, the side panels 72 and the anchor bolts cooperate to preventthe gap between the upper edges of the side walls 41 from being widened.

In the case of steel form, in order to prevent a reduction in thesectional stiffness, stiffening parts for maintaining the relativepositions between the side walls 41 and the bottom slab 42 may beprovided on the bonding portions between the side walls 41 and thebottom slab 42. However, by providing the stiffening parts, thecross-sectional area of the interior of the form 4, in other words, theinner concrete portion 51, becomes smaller, and the space available forarranging the reinforcing bars 52 will be limited.

In addition, the reinforcing bars 52 will not be arranged in thevicinity of the bottom slab 42 within the inner concrete portion 51where the bending stress is large; as a result, there is a possibilitythat the strength of the table deck will be lowered. In the case ofconcrete form, which has a greater thickness compared with steel form,the impact is particularly significant.

This problem can be solved by connecting the upper edge portions of thepair of side walls by using the upper-surface connecting part 7according to the present invention. By attaching the upper-surfaceconnecting part 7 so as to be set over the pair of side walls 41 in thisway, when the form 4 is hoisted by a crane and when concrete is pouredinto the form 4 to form the inner concrete portion 51, the gap betweenthe upper edge portions of the pair of side walls 41 is prevented frombeing widened.

FIG. 8 is a sectional view for explaining the configuration of the formof FIG. 6 before the inner concrete is poured.

Furthermore, as shown in FIG. 8, the inner reinforcing bars 52 of theload portion 5 are arranged inside the form 4.

At the same time, as shown in FIG. 7, the embedded metal parts 6 aresupported by the slotted holes 71 provided in the upper-surfaceconnecting part 7, and the arrangement positions of the embedded metalparts 6 are maintained by the upper-surface connecting part 7.

FIG. 9 is a schematic view for explaining a state for constructingconnecting portions between the piers and the form.

As shown in FIGS. 3 and 9, a step of constructing connecting portions 21is conducted after the form 4 is set on the piers 2 (Step S4).

The connecting portions 21 connect the piers 2 with the form 4, in otherwords, with the table-deck portion 3, and connect both end portions ofthe form 4 with the upper ends of the piers 2.

More specifically, the construction is conducted as described below.

The form 4 is first placed on the two piers 2 such that the form 4 isset on the two piers 2. Next, the reinforcing bars provided inside theform 4 and the reinforcing bars sticking out from the upper ends of thepiers 2 are connected by reinforcing bars for connection. Then, form 22is set around the space in which the connected reinforcing bars arepositioned.

Thereafter, as shown in FIG. 3, a step of adjusting the arrangementpositions of the embedded metal parts 6 is conducted (Step S5). Forexample, as shown in FIG. 7, the arrangement positions of the embeddedmetal parts 6 are adjusted by moving the embedded metal parts 6 alongthe slotted hole 71 of the upper-surface connecting part 7.

Furthermore, by loosening the two anchor bolts 73, the upper-surfaceconnecting part 7 can be shifted in its width-wise direction to achievefine adjustment. By doing so, two-dimensional fine adjustment of theembedded metal parts 6 in the horizontal plane can be conducted.

In this embodiment, although a configuration in which the slotted holes71 extend in the longitudinal direction of the upper-surface connectingpart 7 and the slotted holes 75 extend in the width-wise direction ofthe upper-surface connecting part 7 is illustrated, a configuration inwhich the slotted holes 71 extend in the width-wise direction of theupper-surface connecting part 7 and the slotted holes 75 extend in thelongitudinal direction of the upper-surface connecting part 7 is alsopossible.

Thereafter, as shown in FIG. 3, concrete is poured into the form 4 toform the inner concrete portion 51, and at the same time, concrete isalso poured into the form 22, and a concrete curing step is conducted(Step S6).

As shown in FIG. 2, once the concrete is poured into the form 4 to formthe inner concrete portion 51, the interior of the form 4 is filled withthe inner concrete portion 51 to form the load portion 5, and parts ofthe embedded metal parts 6 are embedded in the inner concrete portion51.

Thereafter, while the poured concrete is curing, a step of removing thescaffolding set around the platform 1 is conducted (Step S7), andsubsequently, the upper-surface connecting part 7 is removed from theside walls 41 by removing the anchor bolt 73. Thus, the platform 1 asshown in FIG. 1 is completed.

According to the configuration described above, a step of forming theform 4 and a step of building a plurality of piers 2 can be conductedsimultaneously, and at the same time, the form 4 can be made at adifferent site from the construction site of the plurality of piers 2,in other words, the construction site of the platform 1. Therefore, areduction in the construction period, that is, the production period ofthe platform 1, can be achieved.

Furthermore, because the form 4 is made of concrete, the form 4 is notrequired to be removed after the concrete has been poured into the form4 to form the inner concrete portion 51, and therefore, the constructionperiod can be reduced.

In addition, when form made of steel plates is used, it is necessary toperform welding management, and it is necessary to make the form in afactory in order to ensure dimensional precision. In contrast, when formmade of concrete is used, it is not necessary to perform weldingmanagement etc. Therefore, the site for producing the form is notlimited to the factory; the form can be produced at a suitable siteclose to the construction site, and it is possible to reduce the costsrelated to transport of the form.

On the other hand, because concrete is poured to form the inner concreteportion 51 after the form 4 having the pair of side walls 41 and thebottom slab 42 has been set on the piers, a reduction in the size of acrane used for setting the form can be afforded compared with a casewhere the form 4 is set on the piers 2 after concrete has been poured toform the inner concrete portion 51.

By connecting each of the edge portions of the pair of side walls 41with the upper-surface connecting part 7, a part of the cross-section ofthe form 4 forms a box-structure; therefore, it is possible to prevent areduction in the sectional stiffness of the form 4 due to the wideningof the gap between the edge portions (upper edges) of the side walls 41.Therefore, deformation of the form 4 during pouring of the concrete forthe inner concrete portion 51 is prevented, and no supports forsupporting the form 4 need to be set.

Because the embedded metal parts 6 are supported with the slotted holes71 of the upper-surface connecting part 7, it is possible to align theembedded metal parts 6 easily and with high precision without using aseparate massive template and temporary supporting members thattemporarily support this template from above. Furthermore, theconstruction period can be reduced compared with a process where theembedded metal parts 6 are arranged directly in the form 4 and theirarrangement positions are adjusted.

In addition, as shown in FIG. 7, the upper-surface connecting part 7 iscomposed of an elongated member, thereby achieving weight saving. Bydoing so, the upper-surface connecting part 7 can easily be attached toand detached from the form 4. In addition, because the upper-surfaceconnecting part 7 is finely adjustable in two dimensions in the planardirection of the region that will form the top surface of the table-deckportion 3 after concrete has been poured, the positions of the embeddedmetal parts 6 are two-dimensionally adjustable in the horizontal planeby using this fine adjustment.

The process of constructing the table-deck portion 3 using theabove-described form 4 can also be applied to the construction of thepiers 2, and it is not particularly limited.

REFERENCE SIGNS LIST

-   1 platform (concrete platform)-   2 pier-   3 table-deck portion-   4 form-   6 embedded metal part (attachment part)-   7 upper-surface connecting part (connecting member)-   41 pair of side walls-   42 bottom slab-   51 inner concrete portion-   61 nut (fixing member)-   71 slotted hole (adjusting part)-   75 slotted hole (adjusting part)-   S2 step (Step for forming form)-   S3 step (Step for setting form)-   S6 step (Step for pouring concrete)

What is claimed is:
 1. A concrete platform comprising, at a top portion,a table-deck portion that has a form, a load portion formed in the form,and an attachment part, wherein the form has a cross-sectional U-shape,and is formed by a pair of concrete side walls and a concrete bottomplate that connects the pair of concrete side walls, and wherein theform comprises reinforcing members provided to extend linearly in alongitudinal direction inside the concrete side walls and inside theconcrete bottom plate.
 2. A concrete platform according to claim 1wherein the form is configured so that a connecting member is detachablyattached in such a manner that top end parts of the concrete side wallsare connected by the connecting member, the connecting member is forconnecting the top end parts of the concrete side walls to form the loadportion by pouring concrete into the form.
 3. A concrete platformaccording to claim 2, the connecting member comprising: an elongatedmember that is formed to have substantially the same length as the widthof the gap between the pair of concrete side walls of the form; a firstadjusting part that enables inserting the attachment part into theelongated member; and a second adjusting part that enables theattachment part to move relative to the elongated member along a topsurface of the table-deck portion that is formed by pouring the concreteinto the form.